Advances in sensor technology, electronics, and communications have made it possible for physiological characteristics of patients to be monitored even when the patients are ambulatory and not in continuous, direct contact with a hospital monitoring system. For example, U.S. Pat. No. 5,959,529 describes a monitoring system in which the patient carries a remote monitoring unit with associated physiological sensors. The remote monitoring unit conducts a continuous monitoring of one or more physiological characteristics of the patient according to the medical problem of the patient, an example being the heartbeat and its waveform.
Under prescribed conditions, the remote monitoring unit contacts a central unit to communicate information on the condition of the patient. For example, if the remote monitoring unit determines that the monitored physiological data suggests that the patient may be in distress or in an emergency, it may immediately and automatically transfer the monitored data to the central unit over a cellular telephone or comparable communications device. The central unit automatically, or in conjunction with medical personnel who are stationed at or are in contact with the central unit, analyzes the data and coordinates the provision of assistance to the patient when necessary. Where the analysis of the transmitted data indicates that there is no patient situation requiring immediate attention, the data is stored and may also be forwarded to the patient's physician so that treatments may be altered.
While operable, this approach may in some cases be wasteful of the battery power of the remote monitoring unit and require the expenditure of too much data transfer time over the cellular telephone system with its associated charges. The time of the medical personnel may also be used inefficiently.
There is a need for an improved approach for the control of data transfers between the remote monitoring unit and the central unit. The present invention fulfills this need, and further provides related advantages.